Pathways of phosphorous fraction dynamics in field crop rotations of the pampas of Argentina
The study of labile and nonlabile forms of P might contribute to advances in soil test procedures and provide insights into management strategies to enhance P bioavailability to crops. Our objective was to evaluate the effect of continuous P fertilization on inorganic [Pi] and organic [Po] P fractions to improve the understanding of soil P dynamics. For this purpose, four on-farm experiments were analyzed during a 6-yr period. Two sites followed the corn [Zea mays L.]-double cropped wheat [Triticum aestivum L.]/soybean [Glycine max [L.] Merr.] rotation and two sites followed the corn-soybean-double cropped wheat/soybean rotation. Phosphorus fertilization levels were 0 [Wp treatment] and 34 kg yr -1 [Fp treatment]. The following soil P fractions were analyzed: anion exchange membrane [AEM] Pi, NaHCO 3-Pi and -Po, NaOH-Pi and -Po, HCl-Pi, and residual P. Path analysis of relationships among all P forms revealed that the main P fertilizer sinks were NaOH-Po and HCl-Pi fractions, accounting for approximately 50 percent of total applied P. The pathways for the Wp treatment showed the importance of Pi pools for the replenishment of available P, represented by the AEM-Pi and NaHCO 3-Pi fractions, and the role of NaOH-Pi along with HCl-Pi as major Pi sources. When P fertilizer addition exceeded plant P removal, the pathway analysis showed that the Pi fractions tended to reorganize into more stable Po fractions. Path analysis was a practical tool to elucidate the roles of different Po and Pi pools in the transformations induced by differences in nutrient input and crop removal.
| Main Authors: | , , , |
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| Format: | Texto biblioteca |
| Language: | eng |
| Subjects: | ANION EXCHANGE MEMBRANE, AVAILABLE P, CORN [ZEA MAYS L.], GLYCINE MAX, IN-FIELD, MANAGEMENT STRATEGIES, P REMOVAL, PATH ANALYSIS, PATHWAY ANALYSIS, PHOSPHOROUS FRACTIONS, SOIL TESTS, WHEAT [TRITICUM AESTIVUM L.], AMINO ACIDS, BIOCHEMISTRY, CROPS, FERTILIZERS, LAKES, NITROGEN FIXATION, PHOSPHORUS, REGRESSION ANALYSIS, SOIL TESTING, SOILS, TESTING, ROTATION, AGRICULTURAL MANAGEMENT, BICARBONATE, BIOAVAILABILITY, CROP ROTATION, FERTILIZER APPLICATION, FRACTIONATION, SOIL TYPE, SOYBEAN, WHEAT, PAMPAS, , |
| Online Access: | http://ceiba.agro.uba.ar/cgi-bin/koha/opac-detail.pl?biblionumber=46722 |
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| Summary: | The study of labile and nonlabile forms of P might contribute to advances in soil test procedures and provide insights into management strategies to enhance P bioavailability to crops. Our objective was to evaluate the effect of continuous P fertilization on inorganic [Pi] and organic [Po] P fractions to improve the understanding of soil P dynamics. For this purpose, four on-farm experiments were analyzed during a 6-yr period. Two sites followed the corn [Zea mays L.]-double cropped wheat [Triticum aestivum L.]/soybean [Glycine max [L.] Merr.] rotation and two sites followed the corn-soybean-double cropped wheat/soybean rotation. Phosphorus fertilization levels were 0 [Wp treatment] and 34 kg yr -1 [Fp treatment]. The following soil P fractions were analyzed: anion exchange membrane [AEM] Pi, NaHCO 3-Pi and -Po, NaOH-Pi and -Po, HCl-Pi, and residual P. Path analysis of relationships among all P forms revealed that the main P fertilizer sinks were NaOH-Po and HCl-Pi fractions, accounting for approximately 50 percent of total applied P. The pathways for the Wp treatment showed the importance of Pi pools for the replenishment of available P, represented by the AEM-Pi and NaHCO 3-Pi fractions, and the role of NaOH-Pi along with HCl-Pi as major Pi sources. When P fertilizer addition exceeded plant P removal, the pathway analysis showed that the Pi fractions tended to reorganize into more stable Po fractions. Path analysis was a practical tool to elucidate the roles of different Po and Pi pools in the transformations induced by differences in nutrient input and crop removal. |
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